Abstract -  How ideas from physics and mathematics can be improvised to make simple models to understand how the brain learns, memorizes and does certain other cognitive functions, will be discussed in simple terms. We also attempt to address questions like, 'why the long-term memory is robust against trauma', and 'how words are stored in mental lexicon'. While we deal with associative memory in some detail we discuss ways whereby other forms of memory, such as episodal memory, can be dealt with. We also provide a glimpse of how some of these hypotheses can be tested experimentally.